Decomposer communities and decomposition processes in temperate forests
PhD StudentThalea Stuckenberg
Research OutlineMixing beech forests with Douglas fir and Norway spruce are becoming common practice in Central Europe. It is suspected that the diversity and community of the decomposer system varies according to changes in the composition and diversity of the plants. Plant litter and root exudates serve as main resource of energy and matter for soil organisms and differ in quality and quantity between plant species. It is becoming more evident that bacteria and fungi strongly depend on root-derived resources. This has been shown to vary with site conditions and among tree species in the previous PhD-project of Jingzhong Lu (SP 5-1). Furthermore, Jingzhong Lu showed that oribatid mite but not springtails sensitively respond to variations in stand type.
The aim of this project is to further understand the response of decomposer community, soil food web and decomposition processes to planting pure and mixed stands of beech, spruce and Douglas fir.
To complement the community data of the already studied springtails and oribatid mites gamasid mites will be investigated from the samples that have been collected in 2017.
The functioning of the decomposer system within the different forest stand types is explored with litterbags containing either beech, spruce or Douglas fir leaves and needles. The decomposition of litter is measured by estimating weight loss and analyzing changes in carbon and nitrogen concentrations of the litter.
Based on the results of SP 5-1 the importance of above- and belowground nutrient input by litter and tree roots for the decomposer system will be inspected in a trenching and litter exclusion experiment. Microorganisms (PLFA analysis) as well as meso- and macrofauna (heat extraction) will be studied.